Russia investigates suspects

Over 10,000 guards are stationed on the border between the former Soviet republic of Tajikistan and Afghanistan

MOSCOW, Russia (CNN) --Reports are being investigated that two brothers suspected of involvement in last week's terrorist attacks on the U.S. may have fought in Russia's breakaway republic of Chechnya.

The FSB, successor agency to the KGB, says it cannot confirm intelligence information and a Saudi media report that brothers Nawar and Selim Al-Khazimi were in Chechnya since documents are often forged. However, it is actively investigating the possibility.

Meanwhile, the foreign ministries of Uzbekistan and Tajikistan are denying reports that U.S. warplanes are being moved to the former Soviet republics, both of which border Afghanistan.

The Washington Post is reporting that planes are being sent to Uzbekistan and Tajikistan.

Despite the denials, a former top general who commanded Soviet forces in Afghanistan during its 10-year war in the 1980s says Russia could offer the U.S. the use of its air bases in Tajikistan.

That information, according to Interfax news agency, quotes Boris Gromov as saying Russia could also offer diplomatic help and intelligence information on Afghanistan.